Is my tank over stocked?

[only6foot6]

I currently have a 37 gallon tall tank. I currently have 5 congo tetras, 3 scissortail rasboras, 2 ottos, 2 glass catfish, 3 pristella tetras, 1 red serpae tetra, 1 black skirt tetra and 1 yo yo loach, for a grand total of 18 fish. Do you think this too many fish or perhaps the opposite?

One thing that I have noticed is that most of my fish hang out between the mid to upper levels of my tank. With this being the case, I have a lot of activity at the top but relatively none at the bottom.

If you have any ideas or suggestions, I will be happy to hear them all.

Thanks!!!

[ChilDawg]

I think that you might want to provide enough fish for a school of some of your tetras, but I don't think that there is enough capacity in the tank to add too many. Removal of some fish and then addition to the remaining schooling fish would be a good bet. As for bottom dwellers, I will suggest Cories and Otos. They're my personal faves for the bottom of a tank, but I am sure that you will get other suggestions.

[superstein61]

I believe you have room to safely add around half a dozen more fish.

As far as bottom dwellers, I prefer Clown loaches (you need at least 3), Apistogrammas or Cories

[ChilDawg]

The problem is the mention of the 37g high tank. This greatly reduces the amount of gas exchange which could happen without some subtantial aeration and thus agitation of the surface. I agree that there is room for a few more fish, but not too many due to the lowered amount of gas exchange.

[Heady]

The number of fish means nothing without considering size. For example, my 12" pleco produces a lot more waste than a school of 8 1-1/2" cardinals.

Whether or not you are overstocked also depends on how much filtration you have and whether or not you're concerned about what will happen in a power outage. I.e. if the power goes out, your filter and heater will turn off - but more importantly, there will be virtually no surface disturbance, which is what dissolves the oxygen your fish breathe.

Also this is more of an art than a science. You will hear people say one inch of fish per gallon of water, one inch of fish per 10-12 square inches of surface area, or whatever. Those are good guidelines, but you can fool yourself into thinking you're not overstocked if your fish survive because you have good filtration and the power doesn't go off for long.

Max size x number of fish = Inches of fish
5 congo tetras = 15" of fish
3 scissortail rasboras = 15" of fish
2 ottos = 4" of fish
2 glass catfish = 8" of fish
3 pristella tetras = 6" of fish
1 red serpae tetra = 2" of fish
1 black skirt tetra = 2" of fish
1 yo yo loach = 5" of fish

Giving a total of 57 inches of fish in a 37 gallon aquarium.

That is a lot more fish than I would be comfortable with in my aquarium. However many people would be comfortable with this, and maybe even put more in there. Like I said, if you have good filtration and don't have any extended power outages, you may be fine. If the power goes out for any significant length of time, you're probably going to have losses.

[RTR]

Good reasoning and explanation Heady, I fully agree.

To me the tank is overstocked, but it is sustainable with good filtration and good maintenance so long as there are no problems. If problems arise with power outage, high temperatures, disease, etc., the slippery slope is steep and fast.

[gidget21]

i say you have room for a few more but advise add some that hang out at the bottom all the fish you have like the upper level of the aquarium.

[only6foot6]

Thank you everyone for your advice. I really appreciate everyone's input.

Heady, thank you for the nice breakdown chart regarding fish type vs. maximum size, you brought up some interesting points.

I am currently using an Emperor 280 power filter for my tank. So far, I have been happy with its results. I do not use an air pump but the Emperor creates a nice water movement at the surface.

I also forgot to say that my tank is planted with Java Fern & Anubias. I know this also helps improve the water quality of the tank.

Thanks Again

[superstein61]

Heady, well while I don't disagree with your concept, I do disagree with your application of it.

You are way too aggressive on the maximum size for almost all those fish IMO. Just my opinion.

[Heady]

Most of those maximum sizes were obtained right here from aquaria central; for the ones that aquaria central did not list, I checked at least 2 different websites before settling on a size. Whether fish are actually kept healthy enough to reach their maximum size is another story.

[superstein61]

Those sizes may have come of the website and other sources, but they are very conservative. yea, a few fish reach those sizes, the vast majority do not. the reference sources play it safe and typically list the max extreme rather than what is normal

[RTR]

Define "normal" do you mean the stunted fish out of many beginner's community tanks? Or do you mean what they should reach in uncrowded and healthy conditions? I'll go with the latter definition myself. Probably the majority of hobbyists never see what their fish should be, or should have been had they not been kept in insufficient space. Nor do most hobbyists ever see how long their fish should live, part of the same issue.

We have not even touched on incompatability, although ChilDawg hinted at it.

[superstein61]

By normal I mean that what 80% to 90% of hobbyists experience. Perhaps you consider that "stunted", but that is the reality.

And just so we are on the same page, I follow the thinking that measurements do not include the tail - just the body.

Look at a few of the examples here -

Otto's @ 2 inches - Now, how many people here have Otto's that big? Even Dawes Encyclopedia of Freshwater fish notes the size "up to 2in reported but usually smaller".

Scissortail Rasboras - well, if we are getting conservative, Dawes reports "some up to 6in but usually considerably smaller". How often do you see a 3in Scissortail ? 2in is realistic

A Yo-Yo loach being 5 inches - sure, and I have some nice swampland in Florida that you may be interested in. I have kept loaches for many years and never saw one that large. In fact, Dawes notes "up to 4 1/2in reported but usually much smaller"

Those are just 3 examples. When calculating size in stocking a tank, we should use what is realistic, not the extreme. And that does not automatically mean using as you term, "stunted " fish. Instead it means throwing out the extreme hogh and lows and using what is typically found

[RTR]

You are fully entitled to your own opinion, but personally, I disagree strongly. I don't think I've ever had a scissorstail Rasbora under 3" at maturity - even in the dark ages years ago when I was not nearly as careful as I am now.

The correct term is still (IMHO & IME) stunting.

I did not realize it was as bad as 80-90% of fishkeepers, but I suppose that is possible. I would have to interpret that as meaning that 80-90% of fishkeepers stunt their fish. Sad.

[Heady]

It is my understanding that the lengths given are from head to tail, including the whole fish.

Regardless, if your fish are not full grown and you stock based on their current size, they really never have a chance of reaching their full adult size. Would you keep an entire spawn of goldfish in a 10 gallon tank for their entire lives, just because their size at a month old would have fit the one inch of fish per gallon rule? No! Because most would die before they reach adulthood, partly because they were not given enough space to live. Likewise it is IMO a little silly to overstock a tank with half-grown specimens and expect them to ever reach their adult size and/or be healthy and happy for life. Their growth will likely be stunted; even if their growth is not stunted, they are more likely to die before ever reaching their full adult size.

[superstein61]

RTR - well you too are fully entitled to your own opinion, and as you do with me, I personally strongly disagree with it.

I do not believe that because the majority of fish never reach the maximum size that it is because as stunting. There are reasons why their is a minimum and maximum size. The majority of fish fall somewhere in between.

Stocking based on the maximum size that even under pristine conditions very few fish will reach is extremely conservative and IMO silly.

Now, I am not saying stock based on existing size. instead, one should stock based on a reasonable average size. You picked one example out of the 3 I provided above. Lets me do the same. Look at the yo-yo loach. First off, Dawes doesn't even have them getting up to 5" - he has the max at 4 1/2". but ask most loach keepers and 3" is the norm for a healthy, full grown yo-yo. So IMO, one should stock based on the 3" norm, not the 4 1/2" extreme.

[ChilDawg]

Ottos at 2" is legit. We, as hobbyists, kill them so quickly that there is no possibility of learning what their full sizes will be. That having been said, I have had "Methuselah" for over five months now, and he is almost 1.5" from head to caudal peduncle. It is hard to tell the max. size of a fish when they are so hard to keep, but I would rather go by many literature maximums than risk losing fish due to overcrowding and stunting growth.

[superstein61]

heady - well most of the people I have dealt with, including those I have discussed this with at my local aquarium society do not consider the tail in any measurements.

Next, you are completely missing or misstating my point. I am not saying to stock a tank based on a fish's size today. What I am saying is stock based on the reasonable projected adult size - not the maximum extreme's you have quoted.

IMO, it is very silly to base stocking on what 1 out of a large number of fish may grow to in pristine conditions. I am simply suggesting using norms and common sense.

[ChilDawg]

Okay, tag, superstein...we both got our posts in at approximately the same time, so "tag" is what people use to represent that, I believe.

Now I like your idea, but, being a statistician, I realize that there is an extremely high likelihood of fish living out "natural" lifespans and being within two standard deviations of the norm on either side--much higher than said fish only achieving the norm in growth. I would go a little more conservative than stocking for the norm, but I can somewhat see your point on the lit. maxes.

That does not, however, guarantee that lit. maxes are even close to right for captive conditions. Many of the lit. maxes stated for newer species are much too low, as are some for species which do not have a large following, just recently became available, or just recently became able to be feasibly kept by a vast amount of hobbyists.

I guess that we can all agree to disagree strongly and try to win each other over, but my $.02 are on the table and I hope to see conflicting opinions to repay mine soon.

[OrionGirl]

Actually, there really isn't a huge amount of variability between fish in the wild. Age, gender and dominance within a system will impact size, but otherwise, most fish reach a pretty standard length. I know that when we do population studies, average variation within an age class in pretty minimal--less than an inch. That's impressive, statistically. I've seen the hatchery raceways with 50,000 fish, and there will be 6-10 fish that are more than 1 inch different in size, in either direction. The closer a fish is to F01, the more likely they are to be all the same size. In the wild, being much different in size that your age group is a serious liability. Bigger, and you have to compete with older, wiser fish, smaller, and you can't get as much food as quickly. Schooling fish of the same species will preferentially school with their own size, since the disparity in size makes them stand out, with means they are easily targetted by a predator.

Obviously, comparing fish from a huge reservoir with those from a tiny creek will reveal some huge differences. However, you can legitimately say that their environments impact growth rates. Hence, a fish that is 2-3 inches in the wild should be able to easily reach that 3 inch mark in a home aquarium, since they stresses and limiting factors found in wild populations (ie, food, pollution, competition) can be controlled in an aquarium. If anything, the maxes provided from wild fish may be under-estimates for the potential size the fish could achieve in ideal conditions.

[RTR]

Thank you for informing me that my techniques and suggestions for fish-keeping are considered "silly". Well, if keeping fish in a manner such that they can reach full normal adult size is sily, so be it. I much prefer being considered silly than abusing my fish.

[Heady]

superstein, I am not missing your point. I do think you are a little misguided.

While it is true that many fish kept in aquaria do not reach the full sizes given in the literature, this is because many aquariasts overstock their tanks or otherwise do not provide their fish sufficient room to grow. Many fish will not reach their proper size when they are in overcrowded conditions or when they are kept in a tank that is too small for them. This is just a fact, and it is called "stunting" their growth. Whether you believe in the concept of stunting a fish's growth is irrelevant; the fact is that it happens.

If you base your maximum sizes on average sizes of fish that are kept in that type of environment, then right off the bat you are never giving them a chance to lead a healthy, happy life.

I suspect you may be basing your opinions on sizes of fish at the lfs's. Most of the fish you see at lfs's are not adults but juveniles. It is cost effective and good business sense for the person raising the fish to get one batch out to the store as soon as reasonably possible, so he/she can get on with the next batch. Thus more often than not, the fish stores receive juveniles from their suppliers, and this is what they put in their display tanks. If you are basing your estimates on what you see at the store, you are using juvenile specimens as an estimate of the full adult size.

I, for one, try to treat my pets with respect, compassion, and kindness. I will never knowingly put fish in a tank where they would not be comfortable as full-grown adults, because realistically, this will be their only home for the rest of their lives.

To find out the best possible estimate of full-grown adult fish, I consult references published by experienced hobbyists and well-respected sites. I do not consider these practices "silly", and think you would do well to treat the rest of us here with a little respect, as we do to you.

[ChilDawg]

I didn't see the insulting nature of another post. If forgoing a few extra fish by someone else's standards in order to make sure that your fish are happy is silly, then I will have to count myself silly. Like I said, I could see following the norm maybe, but preparing for the worst is the only option which I see if you follow this path. I wouldn't want a tank based upon the norm to become grossly overstocked or full of stunted and thusly dying fish. So-called silliness is my choice.

[superstein61]

Originally posted by ChilDawg
Okay, tag, superstein...we both got our posts in at approximately the same time, so "tag" is what people use to represent that, I believe.

Now I like your idea, but, being a statistician, I realize that there is an extremely high likelihood of fish living out "natural" lifespans and being within two standard deviations of the norm on either side--much higher than said fish only achieving the norm in growth. I would go a little more conservative than stocking for the norm, but I can somewhat see your point on the lit. maxes.



Childawg - thanks, as a statistician I think you understand better the point I was trying to make. At least some one here understands it ;) I am not saying ignore all the literature. But instead view it as a guide. If you plotted the adult size of a large population of fish, you would get some type of bell curve distribution. I am saying base stocking on the far larger middle portion of the bell curve, and not the extremes which is what RTR and Heady are advocating.

[superstein61]

RTR and Heady - Well, you obviously have one viewpoint, I and others have another. It appears we will never agree, so we should leave it at that.

However, I am not sure why both of you are upset at my post or opinion and have your shorts in an uproar. There was nothing disrespectful about it - and I certainly did not advocate abusing my fish. Just as you are entitled to your opinion, I and others and entitled to ours.

[Heady]

Only6foot6,

I, too, work with statistics on a daily basis for my bread and butter. While there is indeed a bell curve for natural fish sizes, that curve by necessity must be extremely narrow, as Oriongirl pointed out. It would be a detriment to the fish to be far outside the norm of the average size for its group. That fish would likely be naturally selected out of the population through a lack of interested mates or through the more direct way, getting noticed more easily by a predator. Thus the natural size of each species is within rather tight boundaries. Even in an aquarium, the fish is genetically programmed by hundreds of thousands of years' worth of wild generations to reach a particular size which has been proven through natural selection to have the best chance of survival. Just because a specimen is taken from the wild one day and placed in an aquarium does not change this genetically programmed drive to reach a given size.

The sizes given by the literature are not maximum sizes but reasonable expectations of what the adult size of a given fish will be. I quote from Dr. Riehl and Hans Baensch from Baensch's Aquarium Atlas p.204: "[Fish] need a large tank with plenty of space for swimming. When you purchase a young fish you should know, in advance, the size it will attain as an adult."

It is simply a fact, not an opinion, that you can stunt a fish's growth by placing it in an environment where it is overcrowded or where it just does not have enough space to swim. If you use the juvenile's size, or the size of a stunted specimen, as your guide, you are setting your fish up to be in an unhappy and unhealthy situation as it tries to grow naturally but can't. Many fish prematurely die when they cannot reach their normal size in an aquarium. Others survive but cannot reach more than the size of a juvenile. Still others may actually reach their full size despite all the hardship it is up against, only to die later when their master still will not move them to an appropriately sized and stocked tank and the fish is poisoned by its own excrement in a space too small for it.

This is not a fate I would want for any of my pets because I care about them. I give my animals the best chance I can to reach their normal adult size in a comfortably sized aquarium that is not stocked to the hilt with other fish.

[superstein61]

Originally posted by Heady
superstein - It was a little rude of you to call us silly for following the best possible practices, to say that we were completely missing your point, and to say that because we are not statisticians we cannot understand what you are saying.

Rather than resorting to insults as you did, we were trying to have a logical discussion of our viewpoints.




Heady - give it a break already. If I had said you are an idiot or called you some unprintable name, that would be an insult. However nothing I said could logically be viewed as insults by any objective person.

First, I never called you nor RTR silly - what I said was:

"Stocking based on the maximum size that even under pristine conditions very few fish will reach is extremely conservative and IMO silly."

"IMO, it is very silly to base stocking on what 1 out of a large number of fish may grow to in pristine conditions. "

Second, if you consider the use of the word "silly" to be an insult, then why did you choose to use that same "SILLY" word in a post much earlier than any of my responses. I quote:

from Heady 3/28/03 9:30am "Likewise it is IMO a little silly to overstock a tank with half-grown specimens and expect them to ever reach their adult size and/or be healthy and happy for life. "

I guess I should be upset because you were insulting me with the use of the word silly, huh?

Third, as far as missing or misstating my point - Yes, you missed it by a mile IMO. Is that an insult, well golly gee whiz I don't think so. Its an opinion I had based on your response which says:

By Heady "Would you keep an entire spawn of goldfish in a 10 gallon tank for their entire lives, just because their size at a month old would have fit the one inch of fish per gallon rule? No!"

Nowhere in any of my responses did I advocate such a thing. That is a COMPLETE misstatement or missing the point of what I wrote. What I suggested is to not expect all 5 yo-yo loaches you add to grow 5" each as you suggest - but rather go with the normal average adult length which is much lower - and that is a fact in the literature - I quote from Dawes Complete Encyclopedia of the Freshwater Aquarium

"Up to 4 1/2" reported but usually much smaller". Let me repeat that last piece "USUALLY MUCH SMALLER" - so why stock based on 5" as you suggest when the majority of fish reach a maximum length MUCH SMALLER ????????

Finally you suggest you were trying to have a logical discussion. Well so was I. Unfortunately, you and RTR had your mind set that your own point of view was correct and could not see or agree with the point I was trying to make. Thats fine, both of you are entitled to your own opinion and belief - but so am I. Just because someone disagrees with you does not make their remarks insults. Do you really expect everyone to agree with you on these forums????? That IMO would be quite silly indeed. Oops, I better add this after that last sentence:

Disclaimer - the use of the word silly in the last line of this post should in no way be interpreted to be an insult to Heady .

[Heady]

Only6foot6 - I bet you never expected to get as many responses as you have. :) As I have said before, stocking your tank is more an art than a science. Many people have many different viewpoints. In the end, you have to decide for yourself what you think is best for your own fish. Whatever you choose to do, the fish may survive or even thrive, or they may not. There are many factors involved, so you need to decide for yourself based on the information you have about your ideals and your own intimate knowledge of your own tank. My goal is to provide my fish the best possible environment that I can, since my aquarium will the the only home they know for the rest of their lives. You have to think about what is important to you, having as many fish as you possibly can in your tank, or ensuring the fish you do have are as happy and healthy as you can make them. No one can make that decision for you. Regardless, I wish you good luck on whatever you choose to do.

Heady Out.

[OrionGirl]

I think this post has reached it's pinnacle in terms of providing information. It hasn't decayed, and I think I'd like to prevent that.

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